Vertex k8400 X-axis not returning correct to home position

I have a problem with my x-axis if i tell it to go home it does not go too the place it is supposed to go, it goes to x 200 y 200 but in reality the x-axis is at around 190 and every thime i hit home the x-axis goes further to the left but it stays at 200 on my screen. and when it went to the left and still says it is at 200 but actualy is at lets say 160 it can not move it to the right only left.

This sounds like an alignment problem.
Try looking in this link